Assessment of Casual Relations, Direct and Indirect Effects of Latent Covariates On CD4 Cell Count Change Among HIV Positive Adults

Background: The use of structural equation modelling and latent variables remains unusual in epidemiology despite its potential usefulness and assessment of casual relations. Measuring direct and indirect effect of latent variables helps for proper intervention and for the ART program to be effective. The main objective of current investigation was to assess casual relations, direct and indirect effect of latent covariates on CD4 cell count change for HIV positive adults under HAART. Methods: Based on the repeated measures of CD4 cell count change data obtained in ART section at Felege Hiwot Teaching and Specialized hospital, AMOS software was employed parameter estimation. The data was conducted on 792 randomly selected HIV positive adults. The data was collected by the health staff for sake of delivering medication adherence. Results: CD4 cell count change was directly and indirectly affected by the latent variables. The powers of effects of observed variables with and without latent variables were a little bit different from each other. Hence, the power effect of observed variables with latent variables was lower as compared to without latent variables. The direct effect of latent variables on the response variable was a little bit greater than indirect effect. Conclusion: The power of effects of observed variables were stronger than their effects with latent variables. Hence, the latent variables had significant contributions for progress of CD4 cell count change. Health related education about the direct and indirect effect of latent variables should be given for patients under HAART.